A railway-based transportation system, which can travel on a track via travelling wheels with rubber tires, is known as a new transportation system other than a bus or a train. Typically, this type of railway-based transportation system is referred to as a “new transportation system” or an “automated people mover (APM)”. In the railway-based transportation system, guide wheels disposed respectively in the opposite side portions of a vehicle are guided by guide rails provided along the track.
In many cases, the vehicle of the railway-based transportation system has a car body length shorter than that of a typical train vehicle, and thereby, similar to an automobile or a bus, the vehicle includes single-axle bogies at the front and rear of the car body, respectively. In addition, in many cases, when the single-axle bogies are used in the vehicle of the railway-based transportation system, a parallel link method similar to an automobile or the like is adopted for a simple suspension mechanism. In the vehicle of the railway-based transportation system, air springs may be provided between the car body and the bogie so as to absorb roughness of the track and improve ride quality.
The vehicle of the railway-based transportation system is required to enable increased travel speed such that a movement time is reduced or transportation capacity is increased. However, since an unbalanced centrifugal force increases corresponding to an increase in travel speed when the vehicle travels on a curved portion of the track, ride quality and safety may deteriorate.
A typical train vehicle, which includes a car body tilting apparatus configured to tilt a car body inward of the track so as to counteract an unbalanced centrifugal force generated in the curved portion, has been put into practice.
For example, in a technology disclosed in PTLs 1 to 5, the car body is tilted toward the inner rail by setting the respective lengths of a pair of right and left air springs to be different from each other using a height adjustment mechanism of the air springs. According to this technology with a simple configuration, it is possible to tilt the vehicle toward the inner rail.